import urllib.request


url = 'http://www.baidu.com/'

headers = {'User-Agent':'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36 Edg/120.0.0.0'}

request = urllib.request.Request(url = url,headers = headers)

response = urllib.request.urlopen(request)

content = response.read().decode('utf-8')

from lxml import etree

tree = etree.HTML(content)

result = tree.xpath('//input[@id="su"]/@value')[0]

print(result)